Abstract: A coinage cladding alloy for coinage includes nickel present in an amount from 5 wt. % to 7 wt. %, based on a total weight of the coinage cladding alloy; zinc present in an amount from 21 wt. % to 29 wt. %, based on the total weight of the coinage cladding alloy; manganese present in an amount from 12 wt. % to 16 wt. %, based on a total weight of the coinage cladding alloy; copper; an electrical conductivity from 2% International Annealed Copper Standard (IACS) to 3% IACS; and a color comprising a yellowness vector b* that is from 2 to 10, based on a CIE L*a*b* color space and determined in accordance with ASTM Standard E308-15 (2015).

Abstract: A coinage alloy for coinage includes nickel present in an amount from 4 wt. % to 11 wt. %, based on a total weight of the coinage alloy; zinc present in an amount from 20 wt. % to 35 wt. %, based on the total weight of the coinage alloy; manganese present in an amount from 3 wt. % to 6 wt. %, based on a total weight of the coinage alloy; copper; an electrical conductivity from 5% International Annealed Copper Standard (IACS) to 6% IACS measured in accordance with ASTM E1004-09 (2009); and a color comprising a yellowness vector b* that is from 6 to 11, based on a CIE L*a*b* color space and determined in accordance with ASTM Standard E308-15 (2015).

Abstract: A coinage alloy for coinage includes nickel present in an amount from 13 wt. % to 16 wt. %, based on a total weight of the coinage alloy; zinc present in an amount from 25 wt. % to 32 wt. %, based on the total weight of the coinage alloy; manganese present in an amount from 1 wt. % to 4 wt. %, based on a total weight of the coinage alloy; copper; an electrical conductivity from 5% International Annealed Copper Standard (IACS) to 6% IACS; and a color comprising a yellowness vector b* that is from 5 to 10, based on a CIE L*a*b* color space and determined in accordance with ASTM Standard E308-15 (2015).

Abstract: A primary alloy includes: nickel; copper; zinc; an electrical conductivity from 5.2% International Annealed Copper Standard (IACS) to 5.6% IACS measured in accordance with ASTM E1004-09 (2009); and a disordered crystalline phase wherein atoms of the nickel, cooper, and zinc are randomly arranged in the disordered crystalline phase at room temperature in a post-annealed state. A process for making the primary alloy includes heating a secondary alloy to a first temperature that is greater than or equal to an annealing temperature to form an annealing alloy, the secondary alloy including a secondary phase; and quenching, by cooling the annealing alloy from the first temperature to a second temperature that is less than the annealing temperature, under a condition effective to form the primary alloy including the disordered crystalline phase, wherein the disordered crystalline phase is different than the secondary phase of the secondary alloy.

Abstract: A coinage alloy for coinage includes nickel present in an amount from 4 wt. % to 11 wt. %, based on a total weight of the coinage alloy; zinc present in an amount from 20 wt. % to 35 wt. %, based on the total weight of the coinage alloy; manganese present in an amount from 3 wt. % to 6 wt. %, based on a total weight of the coinage alloy; copper; an electrical conductivity from 5% International Annealed Copper Standard (IACS) to 6% IACS measured in accordance with ASTM E1004-09 (2009); and a color comprising a yellowness vector b* that is from 6 to 11, based on a CIE L*a*b* color space and determined in accordance with ASTM Standard E308-15 (2015).

Abstract: A coinage cladding alloy for coinage includes nickel present in an amount from 5 wt. % to 7 wt. %, based on a total weight of the coinage cladding alloy; zinc present in an amount from 21 wt. % to 29 wt. %, based on the total weight of the coinage cladding alloy; manganese present in an amount from 12 wt. % to 16 wt. %, based on a total weight of the coinage cladding alloy; copper; an electrical conductivity from 2% International Annealed Copper Standard (IACS) to 3% IACS; and a color comprising a yellowness vector b* that is from 2 to 10, based on a CIE L*a*b* color space and determined in accordance with ASTM Standard E308-15 (2015).

Abstract: A coinage alloy for coinage includes nickel present in an amount from 13 wt. % to 16 wt. %, based on a total weight of the coinage alloy; zinc present in an amount from 25 wt. % to 32 wt. %, based on the total weight of the coinage alloy; manganese present in an amount from 1 wt. % to 4 wt. %, based on a total weight of the coinage alloy; copper; an electrical conductivity from 5% International Annealed Copper Standard (IACS) to 6% IACS; and a color comprising a yellowness vector b* that is from 5 to 10, based on a CIE L*a*b* color space and determined in accordance with ASTM Standard E308-15 (2015).

Abstract: A primary alloy includes: nickel; copper; zinc; an electrical conductivity from 5.2% International Annealed Copper Standard (IACS) to 5.6% IACS measured in accordance with ASTM E1004-09 (2009); and a disordered crystalline phase wherein atoms of the nickel, cooper, and zinc are randomly arranged in the disordered crystalline phase at room temperature in a post-annealed state. A process for making the primary alloy includes heating a secondary alloy to a first temperature that is greater than or equal to an annealing temperature to form an annealing alloy, the secondary alloy including a secondary phase; and quenching, by cooling the annealing alloy from the first temperature to a second temperature that is less than the annealing temperature, under a condition effective to form the primary alloy including the disordered crystalline phase, wherein the disordered crystalline phase is different than the secondary phase of the secondary alloy.

Abstract: An ionization gas sensor includes a first electrode and a second electrode, such as cathode and anode electrodes. The second electrode is a carbon nanotube film having a carbon nanotube density such that the film behaves as a conducting sheet electrode. The sensor also includes a voltage source electrically connected to the first and to the second electrodes.